Abstract
Purpose: :
Pathologies affecting neurological processing are hypothesized to have an impact on the visual system at a higher rate than the general population. In addition to traditional Snellen acuities, the threshold strategy test in the Frequency Doubling Technology was used as a screening tool to evaluate patients with an identified disease of the neurological system and age matched controls with no neurological diagnosis.
Methods: :
Patients and family members presenting for care in neurology clinics affiliated with Boston University were invited to participate in a vision screening that included a brief visual history, distance acuities and FDT. The FDT is believed to have the capacity to isolate retinal ganglion cells in the magnocellular pathway by utilizing a low spatial frequency sinusoidal grating (<1 cyc/degree) that undergoes a high temporal frequency counter phase flicker at 25 Hz or greater. Back lit flashed images are viewed on a fixed, flat, shielded screen in front of a stationary subject. The patient perceives the targets as small, striped square-shaped areas in either central or peripheral vision.
Results: :
Fifty nine of the patients scheduled for care in the neurology clinic were tested and thirty four adults accompanying a patient scheduled for care were tested. There was a higher rate of failure among those patients with a neurological diagnosis than among the control participants.
Conclusions: :
Based on those patients presenting for care, there is higher rate of visual deficits warranting further examination in patients diagnosed with a neurological disease compared to an age matched population not identified as having a diagnosis of a neurological disease.
Keywords: visual fields • neuro-ophthalmology: cortical function/rehabilitation • pathology: human